WO2017061424A1 - Positive electrode, secondary battery, and method for using secondary battery - Google Patents

Positive electrode, secondary battery, and method for using secondary battery Download PDF

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Publication number
WO2017061424A1
WO2017061424A1 PCT/JP2016/079485 JP2016079485W WO2017061424A1 WO 2017061424 A1 WO2017061424 A1 WO 2017061424A1 JP 2016079485 W JP2016079485 W JP 2016079485W WO 2017061424 A1 WO2017061424 A1 WO 2017061424A1
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positive electrode
group
active material
electrode active
carbon atoms
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PCT/JP2016/079485
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French (fr)
Japanese (ja)
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征太郎 山口
宮田　壮
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リンテック株式会社
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a positive electrode with excellent cycle characteristics and a high-capacity secondary battery, a secondary battery including the positive electrode, and a method of using the secondary battery.
  • Patent Document 1 discloses a positive electrode active material for a secondary battery containing two specific types of oxides, which contributes to improving the cycle characteristics of a 5V class secondary battery and the reliability of high-temperature operation.
  • a secondary battery using such a positive electrode active material with a high operating potential may have a sudden decrease in discharge capacity when the upper limit of the cutoff voltage during charging is increased and charging and discharging are repeated. There was a problem. For this reason, in order not to reduce the discharge capacity even after repeated charging and discharging, it is necessary to lower the upper limit of the cut-off voltage during charging, and it has been difficult to use as a high-capacity battery.
  • the present invention has been made in view of the above circumstances, and is excellent in cycle characteristics (refers to a property in which the discharge capacity is not easily lowered even after repeated charge and discharge), and a positive electrode from which a high-capacity secondary battery is obtained, It aims at providing the secondary battery provided with this positive electrode, and the usage method of this secondary battery.
  • the present inventors diligently studied to solve the above problems. As a result, the current collector, the positive electrode active material layer formed on the current collector, and a specific amount of a specific ionic polymer formed on the positive electrode active material layer are contained, and the basis weight is specified.
  • a secondary battery including a positive electrode having an ionic polymer layer in an amount is found to have excellent cycle characteristics and a high capacity, and the present invention has been completed.
  • a positive electrode comprising a current collector, a positive electrode active material layer formed on the current collector, and an ionic polymer layer formed on the positive electrode active material layer, wherein the positive electrode active material
  • the layer contains a positive electrode active material, and the ionic polymer layer has the following formula (I)
  • R 1 and R 2 are each independently hydrogen.
  • C1-C10 alkyl group with or without atoms, ether bonds, C2-C11 cyanoalkyl groups with or without ether bonds, C2-C10 alkenyl groups with or without ether bonds Or an aryl group having 6 to 20 carbon atoms, with or without a substituent, R 1 and R 2 may be bonded to each other to form a ring.
  • a positive electrode comprising an ionic polymer having a repeating unit derived from the monomer represented by formula (1), wherein the ionic polymer layer has a basis weight of 0.01 to 10 mg / cm 2 .
  • Said X is following formula (II) or (III)
  • R 3 represents a hydrogen atom or a methyl group
  • a 1 represents an alkylene group having 1 to 18 carbon atoms
  • a 2 and A 4 each independently represents an alkylene group having 1 to 5 carbon atoms
  • 3 represents a single bond or an alkylene group having 1 to 5 carbon atoms
  • m represents an integer of 0 to 10
  • n represents an integer of 0 to 10
  • * represents a bond.
  • the positive electrode according to (1) which is a group represented by: (3) The positive electrode according to (1) or (2), wherein the positive electrode active material layer contains a binder resin.
  • a secondary battery comprising the positive electrode, negative electrode, and electrolyte component according to any one of (1) to (4).
  • a positive electrode with excellent cycle characteristics and a high-capacity secondary battery a secondary battery including the positive electrode, and a method of using the secondary battery.
  • the present invention will be described in detail by dividing it into 1) a positive electrode, and 2) a secondary battery and a method for using the secondary battery.
  • the positive electrode of the present invention has a current collector, a positive electrode active material layer formed on the current collector, and an ionic polymer layer formed on the positive electrode active material layer.
  • the positive electrode active material layer contains a positive electrode active material
  • the ionic polymer layer comprises an ionic polymer having a repeating unit derived from the monomer represented by the formula (I).
  • the basis weight of the ionic polymer layer is 0.01 to 10 mg / cm 2 .
  • the current collector constituting the positive electrode of the present invention is capable of holding the positive electrode active material layer and further capable of transferring electrons to and from the positive electrode active material contained in the positive electrode active material layer.
  • the material of the positive electrode current collector is not particularly limited.
  • metal materials and conductive polymers such as aluminum, nickel, iron, stainless steel, titanium, and copper can be used.
  • the positive electrode active material layer constituting the positive electrode of the present invention is formed on the current collector.
  • the positive electrode active material layer contains a positive electrode active material.
  • a positive electrode active material a known material can be appropriately used as the positive electrode active material of the secondary battery.
  • the positive electrode active material LiMn 2 O 4 , LiCoO 2 , LiNiO 2 , Li (Ni—Mn—Co) O 2 (for example, LiNi 1/3 Mn 1/3 Co 1/3 O 2 ), and these Examples thereof include inorganic active materials such as those in which a part of the transition metal is substituted with another element.
  • the positive electrode active material layer may contain a binder resin and a conductive additive.
  • the binder resin is not particularly limited, and known materials can be appropriately used. Binder resins include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), polyimide (PI), polyamideimide (PAI), carboxymethylcellulose (CMC), and polyvinyl chloride (PVC). ), Methacrylic resin (PMA), polyacrylonitrile (PAN), modified polyphenylene oxide (PPO), polyethylene oxide (PEO), polyethylene (PE), polypropylene (PP) and the like.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • SBR styrene-butadiene rubber
  • PI polyimide
  • PAI polyamideimide
  • CMC carboxymethylcellulose
  • PVC polyvinyl chloride
  • PMA Methacryl
  • the conductive aid is not particularly limited, and known materials can be used as appropriate.
  • the conductive assistant include carbon black, graphite, graphite, carbon nanotube, acetylene black (AB), ketjen black (KB), and vapor grown carbon fiber.
  • the ionic polymer layer constituting the positive electrode of the present invention has the following formula (I)
  • X represents a group having a polymerizable carbon-carbon double bond and one bond
  • Y represents an alkylene group having 2 to 5 carbon atoms
  • R 1 and R 2 are each independently hydrogen.
  • C1-C10 alkyl group with or without atoms, ether bonds, C2-C11 cyanoalkyl groups with or without ether bonds, C2-C10 alkenyl groups with or without ether bonds Or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, R 1 and R 2 may be bonded to each other to form a ring.
  • the ionic polymer which has a repeating unit derived from the monomer shown by is contained.
  • the kind of polymerizable carbon-carbon double bond contained in X is not particularly limited. However, as will be described later, when the synthesis of the ionic polymer and the formation of the ionic polymer layer are simultaneously performed (that is, the ionic polymer is synthesized by a bulk polymerization reaction), the ionic polymer layer is efficiently used.
  • the polymerizable carbon-carbon double bond is preferably one that can participate in the radical polymerization reaction because it can be formed well.
  • Examples of the polymerizable carbon-carbon double bond include double bonds contained in an acryloyl group, a methacryloyl group, a vinyl group, and an allyl group.
  • Examples of X include groups represented by the following formula (II) or (III).
  • R 3 represents a hydrogen atom or a methyl group.
  • a 1 represents an alkylene group having 1 to 18 carbon atoms
  • a 2 and A 4 each independently represents an alkylene group having 1 to 5 carbon atoms
  • a 3 represents a single bond or an alkylene group having 1 to 5 carbon atoms.
  • Examples of the alkylene group having 1 to 18 carbon atoms of A 1 include a linear alkylene group such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a pentamethylene group; a propane-1,2-diyl group, butane-1 , 3-diyl group, and the like.
  • alkylene group having 1 to 5 carbon atoms of A 2 and A 4 examples include a linear alkylene group such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a pentamethylene group; a propane-1,2-diyl group, Examples thereof include branched alkylene groups such as butane-1,3-diyl group.
  • n represents an integer of 0 to 10, preferably 0 to 5, more preferably 0 to 3. * Represents a bond.
  • the group represented by X examples include vinyl group, allyl group, 2- (methacryloyloxy) ethyl group, 2- (acryloyloxy) ethyl group, 3- (methacryloyloxy) propyl group, 3- (acryloyloxy). ) Propyl group and the like.
  • the group represented by X is preferably a vinyl group, an allyl group, a 2- (methacryloyloxy) ethyl group, or a 2- (acryloyloxy) ethyl group.
  • Y represents an alkylene group having 2 to 5 carbon atoms.
  • alkylene group having 2 to 5 carbon atoms of Y include linear alkylene groups such as ethylene group, trimethylene group, tetramethylene group and pentamethylene group; propane-1,2-diyl group, butane-1,3-diyl And a branched alkylene group such as a group.
  • R 1 and R 2 each independently have a hydrogen atom, an alkyl group having 1 to 10 carbon atoms with or without an ether bond, a cyanoalkyl group having 2 to 11 carbon atoms with or without an ether bond, and an ether bond. Alternatively, it represents an alkenyl group having 2 to 10 carbon atoms which does not have, or an aryl group having 6 to 20 carbon atoms which may or may not have a substituent. R 1 and R 2 may be bonded to each other to form a ring.
  • the number of carbon atoms of the alkyl group having 1 to 10 carbon atoms of the alkyl group having 1 to 10 carbon atoms with or without an ether bond of R 1 and R 2 is preferably 1 to 8, and more preferably 1 to 5.
  • Examples of the alkyl group having no ether bond include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group.
  • Examples of the alkyl group having an ether bond include groups represented by the following formulas.
  • R 4 represents an alkyl group having 1 to 8 carbon atoms
  • Z 1 represents an alkylene group having 2 to 9 carbon atoms
  • the total number of carbon atoms of R 4 and Z 1 is 3 to 10
  • R 5 represents an alkyl group having 1 to 6 carbon atoms
  • Z 2 represents an alkylene group having 2 to 7 carbon atoms
  • Z 3 represents an alkylene group having 2 to 7 carbon atoms
  • R 5 (The total number of carbon atoms of Z 2 and Z 3 is 5 to 10. * represents a bond.)
  • the number of carbon atoms of the cyanoalkyl group having 2 to 11 carbon atoms in the cyanoalkyl group having 2 to 11 carbon atoms with or without an ether bond of R 1 and R 2 is preferably 2 to 9, and more preferably 2 to 6 .
  • Examples of the cyanoalkyl group having no ether bond include a cyanomethyl group, a 2-cyanoethyl group, a 3-cyanopropyl group, a 4-cyanobutyl group, and a 6-cyanohexyl group.
  • Examples of the cyanoalkyl group having an ether bond include groups represented by the following formulas.
  • R 6 represents a cyanoalkyl group having 2 to 9 carbon atoms
  • Z 4 represents an alkylene group having 2 to 9 carbon atoms
  • the total number of carbon atoms of R 6 and Z 4 is 4 to 11
  • R 7 represents a cyanoalkyl group having 2 to 7 carbon atoms
  • Z 5 represents an alkylene group having 2 to 7 carbon atoms
  • Z 6 represents an alkylene group having 2 to 7 carbon atoms
  • R 7 , Z 5 and Z 6 have a total carbon number of 6 to 11. * represents a bond.
  • the carbon number of the alkenyl group having 2 to 10 carbon atoms of the alkenyl group having 2 to 10 carbon atoms with or without an ether bond of R 1 and R 2 is preferably 2 to 9, and more preferably 2 to 6.
  • Examples of the alkenyl group having no ether bond include a vinyl group, an allyl group, a 1-butenyl group, a 2-butenyl group, and a 1-pentenyl group.
  • Examples of the alkenyl group having an ether bond include groups represented by the following formulas.
  • R 8 represents an alkenyl group having 2 to 8 carbon atoms
  • Z 7 represents an alkylene group having 2 to 8 carbon atoms
  • the total number of carbon atoms of R 8 and Z 7 is 4 to 10
  • R 9 represents an alkenyl group having 2 to 6 carbon atoms
  • Z 8 represents an alkylene group having 2 to 6 carbon atoms
  • Z 9 represents an alkylene group having 2 to 6 carbon atoms
  • R 9 (The total number of carbon atoms of Z 8 and Z 9 is 6 to 10. * represents a bond.)
  • the aryl group having 6 to 20 carbon atoms and having or not having a substituent of R 1 and R 2 preferably has 6 to 10 carbon atoms.
  • Examples of the unsubstituted aryl group include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.
  • Examples of the substituent of the aryl group having a substituent include an alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group; an alkoxy group having 1 to 6 carbon atoms such as a methoxy group and an ethoxy group; a fluorine atom and a chlorine atom And the like.
  • Examples of the ring formed by combining R 1 and R 2 include a pyrrolidine ring and a piperidine ring.
  • the method for synthesizing the monomer represented by the formula (I) is not particularly limited.
  • the monomer (3) can be obtained by reacting the corresponding amine compound (1) with the sultone compound (2).
  • the amine compound (1) can be produced and obtained by a known method. Moreover, in this invention, a commercial item can also be used as an amine compound (1).
  • sultone compound (2) examples include 1,2-ethane sultone, 1,3-propane sultone, 1,4-butane sultone, 2,4-butane sultone, and 1,5-pentane sultone. These are known compounds and can be produced and obtained by known methods. Moreover, in this invention, a commercial item can also be used as these sultone compounds.
  • the amount of the sultone compound (2) used is preferably 0.8 to 1.2 equivalents, more preferably 0, relative to the amine compound (1). .9 to 1.1 equivalents.
  • the reaction of the amine compound (1) and the sultone compound (2) may be performed without a solvent or in the presence of an inert solvent.
  • Inert solvents used include ether solvents such as tetrahydrofuran and diglyme; nitrile solvents such as acetonitrile and propionitrile; ketone solvents such as acetone and methyl ethyl ketone; aromatic hydrocarbon solvents such as toluene and xylene; chloroform and the like And halogenated hydrocarbon solvents.
  • the amount used is not particularly limited, but is usually 1 to 100 parts by mass with respect to 1 part by mass of the amine compound (1).
  • the reaction temperature is not particularly limited, but is usually in the range of 0 to 200 ° C, preferably 10 to 100 ° C, more preferably 20 to 60 ° C. Further, the reaction may be carried out under normal pressure (atmospheric pressure), or the reaction may be carried out under pressurized conditions.
  • the reaction time is not particularly limited, but is usually 12 to 332 hours, preferably 24 to 168 hours.
  • the reaction is preferably performed in an inert gas atmosphere such as nitrogen gas or argon gas from the viewpoint of preventing the yield from decreasing due to oxidation by oxygen or hydrolysis of the sultone compound (2) by moisture in the air.
  • the progress of the reaction can be confirmed by ordinary analytical means such as gas chromatography, high performance liquid chromatography, thin layer chromatography, NMR, IR and the like.
  • the method for synthesizing the ionic polymer is not particularly limited.
  • an ionic polymer is synthesized by performing a polymerization reaction using a radical polymerization initiator. Can do.
  • Examples of the radical polymerization initiator include organic peroxides and azo compounds.
  • organic peroxides include diacyl peroxides such as lauroyl peroxide and benzoyl peroxide; 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) 3,3 Peroxyketals such as 1,5-trimethylcyclohexane; peroxydicarbonates such as diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate; t-butylperoxy-2-ethylhexanoate, t- And peroxyesters such as butyl peroxyisobutyrate.
  • azo compound 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane 1-carbonitrile), 2,2 '-Azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate), 4 , 4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile), 2,2'-azobis [2- (2-imidazolin-2-yl) propane] Etc.
  • these can be used individually by 1 type or in mixture of 2 or more types.
  • the amount of the radical polymerization initiator used is usually 0.25 to 4 times mol, preferably 0.4 to 2 times mol for 1 mol of the monomer represented by the formula (I). The details of the radical polymerization reaction will be described in the method for producing the positive electrode.
  • the positive electrode of the present invention has an ionic polymer layer having a basis weight of 0.01 to 10 mg / cm 2 .
  • the basis weight of the ionic polymer layer is preferably 0.01 to 5 mg / cm 2 , more preferably 0.1 to 1 mg / cm 2 .
  • a secondary battery having a positive electrode with an amount of less than 0.01 mg / cm 2 tends to be inferior in cycle characteristics. Moreover, even if this amount exceeds 10 mg / cm ⁇ 2 >, the effect corresponding to it is not acquired.
  • the basis weight of the ionic polymer layer refers to the mass of 1 cm 2 of the ionic polymer layer. When an ionic polymer layer consists only of an ionic polymer, the basic weight of an ionic polymer layer is the quantity of the said ionic polymer contained per 1 cm ⁇ 2 > of positive electrode surfaces.
  • the positive electrode of the present invention can be produced by forming a positive electrode active material layer on a current collector and then forming an ionic polymer layer on the positive electrode active material layer.
  • the method for forming the positive electrode active material layer is not particularly limited.
  • a positive electrode active material layer-forming coating solution obtained by dissolving or suspending a positive electrode active material, a binder resin, and a conductive auxiliary agent in an appropriate solvent was applied on a current collector, and obtained.
  • the positive electrode active material layer can be formed by drying the coating film. Moreover, you may perform a pressurization process with respect to the coating film after drying as needed.
  • the solvent used for preparing the coating liquid for forming the positive electrode active material layer is not particularly limited.
  • Solvents used include amide solvents such as N-methylpyrrolidone, N, N-dimethylformamide and N, N-dimethylacetamide; ketone solvents such as methyl ethyl ketone and cyclohexanone; ester solvents such as methyl acetate and ethyl acetate; toluene And aromatic solvents such as xylene;
  • the method for applying the positive electrode active material layer forming coating solution is not particularly limited.
  • the coating liquid for forming the positive electrode active material layer can be applied using a coating apparatus such as a die coater, a gravure coater, a doctor blade or the like.
  • the drying conditions of the coating film are not particularly limited.
  • the temperature can be appropriately set at 30 to 150 ° C. within a range of 1 minute to 12 hours.
  • the method is not particularly limited.
  • the pressure treatment can be performed by a roll press method or a surface press method.
  • the pressurizing condition can be appropriately set within a range of 1 minute to 12 hours at 20 to 100 ° C. and 100 to 2000 kg / cm.
  • the processing conditions can be appropriately set at 20 to 100 ° C. and 1 to 20 MPa in the range of 1 minute to 12 hours.
  • the formation method of an ionic polymer layer is not specifically limited.
  • an ionic polymer layer-forming coating solution ( ⁇ ) obtained by dissolving or suspending an ionic polymer in a suitable solvent is applied onto the positive electrode active material layer, and the resulting coating film is applied.
  • a method of forming an ionic polymer layer by drying (Method 1), or an ionicity obtained by dissolving or suspending the monomer represented by the formula (I) and a radical polymerization initiator in an appropriate solvent By coating the coating liquid for forming a polymer layer ( ⁇ ) on the positive electrode active material layer and drying the coating film obtained as necessary, by polymerizing the monomers in the coating film, The method (method 2) etc. which form an ionic polymer layer are mentioned.
  • the solvent constituting the ionic polymer layer-forming coating solution ( ⁇ ) can dissolve or disperse monomers and the like. If the wettability is not low (if it does not repel even if applied), there is no particular limitation.
  • the solvent used is preferably a halogen-containing alcohol such as trichloromethanol, 2,2,2-trichloroethanol, or 3-chloro-1-propanol because a more uniform solution or dispersion can be easily obtained.
  • the method of coating the ionic polymer layer forming coating solution ( ⁇ ) on the positive electrode active material layer is not particularly limited.
  • the ionic polymer layer forming coating solution ( ⁇ ) can be applied in the same manner as the method shown as the method for applying the positive electrode active material layer forming coating solution.
  • the drying conditions of the coating film are not particularly limited. It can be appropriately set at 30 to 150 ° C. within a range of 1 minute to 12 hours. In addition, you may perform the drying of a coating film, and the polymerization reaction of a monomer simultaneously, without distinguishing a drying process and a subsequent polymerization reaction process.
  • the coating film is brought to a predetermined temperature. What is necessary is just to heat.
  • the heating condition is not particularly limited as long as it is a temperature at which the monomer radical polymerization reaction proceeds.
  • the heating temperature is usually 40 to 150 ° C. and can be appropriately set within a range of 1 minute to 12 hours.
  • the positive electrode of the present invention has a current collector, a positive electrode active material layer formed on the current collector, and an ionic polymer layer formed on the positive electrode active material layer. By using this positive electrode, a secondary battery having excellent cycle characteristics and high capacity can be obtained.
  • the secondary battery of the present invention has the positive electrode, the negative electrode, and the electrolyte component of the present invention.
  • the negative electrode constituting the secondary battery of the present invention usually includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode may be composed of only the negative electrode active material layer (that is, the negative electrode active material layer also serves as the negative electrode current collector).
  • the negative electrode current collector holds the negative electrode active material layer and bears an electron transfer with the negative electrode active material. Examples of the material constituting the negative electrode current collector include the same materials as those shown for the positive electrode current collector.
  • the negative electrode active material layer is a layer formed on the surface of the negative electrode current collector, and contains a negative electrode active material.
  • the negative electrode active material examples include carbon materials such as graphite, soft carbon, and hard carbon; lithium-transition metal composite oxides such as Li 4 Ti 5 O 12 ; silicon materials such as silicon simple substance, silicon oxide, and silicon alloy; lithium metal A lithium-metal alloy such as lithium-tin or a lithium-silicon alloy; a simple substance such as a tin material, an alloy or a compound; a simple substance or an alloy of a metal of Group 1 or Group 2 of the periodic table such as sodium, potassium or magnesium; Compound: Sulfur or composite materials using these materials in combination.
  • the negative electrode active material layer may contain other components in addition to the negative electrode active material. Examples of other components include a binder resin and a conductive aid. Examples of the binder resin and the conductive auxiliary contained in the negative electrode active material layer include the same ones as those shown as the binder resin and the conductive auxiliary in the positive electrode active material layer.
  • the electrolyte component constituting the secondary battery of the present invention is not particularly limited.
  • the electrolyte component include a non-aqueous electrolyte obtained by dissolving an electrolyte salt in an organic solvent, an inorganic solid electrolyte, a polymer electrolyte, and the like.
  • the electrolyte salt constituting the non-aqueous electrolyte is an ionic compound containing a metal ion of Group 1 or Group 2 of the periodic table.
  • the metal ions include alkali metal ions such as lithium ions, sodium ions, and potassium ions; magnesium ions; alkaline earth metal ions such as calcium ions and strontium ions.
  • the anion of the electrolyte salt include Cl ⁇ , Br ⁇ , I ⁇ , AlCl 4 ⁇ , Al 2 Cl 7 ⁇ , BF 4 ⁇ , B (CN) 4 ⁇ , PF 6 ⁇ , ClO 4 ⁇ , NO 3.
  • lithium salt As the electrolyte salt, a lithium salt is preferable.
  • lithium salts include lithium bis (fluoromethanesulfonyl) amide (LiN (SO 2 CH 2 F) 2 ), lithium bis (trifluoromethanesulfonyl) amide (LiN (SO 2 CF 3 ) 2 ), lithium bis (2,2 , 2-trifluoroethanesulfonyl) amide (LiN (SO 2 C 2 H 2 F 3 ) 2 ), lithium bis (pentafluoroethanesulfonyl) amide (LiN (SO 2 C 2 F 5 ) 2 ), lithium bis (fluoro Sulfonyl) amide (LiN (SO 2 F) 2 ), lithium tris (trifluoromethanesulfonyl) methide (LiC (SO 2 CF 3 ) 3 ), lithium trifluoromethanesulfonate (LiCF 3 SO 3 ), lithium hex
  • Examples of the organic solvent include carbonate solvents, ester solvents, lactone solvents, ether solvents, nitrile solvents, and sulfur-containing solvents.
  • Examples of carbonate solvents include dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl ethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, or fluorines thereof.
  • Examples of the ester solvent include n-methyl acetate, n-ethyl acetate, n-propyl acetate, and dimethyl acetate.
  • lactone solvent examples include ⁇ -butyrolactone, valerolactone, mevalonolactone, caprolactone and the like.
  • ether solvents include cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran; chain ethers such as dibutyl ether, 1,2-dimethoxyethane, 1,2-dibutoxyethane, and 1,4-dioxane; It is done.
  • nitrile solvents examples include acetonitrile and propionitrile.
  • sulfur-containing solvent examples include sulfolane and dimethyl sulfoxide.
  • the separator has a function of allowing ions to pass through while preventing a short circuit by insulating the positive electrode and the negative electrode.
  • the material constituting the separator include a porous body formed of an insulating plastic such as polyethylene, polypropylene, and polyimide, and inorganic fine particles such as silica gel.
  • Examples of the inorganic solid electrolyte include lithium nitride and lithium iodide.
  • Examples of the polymer compound constituting the polymer electrolyte include polyethylene oxide, polypropylene oxide, polyphosphazene, polyaziridine, polyethylene sulfide, polyvinyl alcohol, polyvinylidene fluoride, polyhexafluoropropylene, and a fluorine-based polymer compound.
  • the electrolyte component may contain an additive such as an ionic liquid (referring to an ionic compound that exists as a liquid at 30 ° C.), a plastic crystal, and a zwitterionic compound.
  • an ionic liquid referring to an ionic compound that exists as a liquid at 30 ° C.
  • a plastic crystal referring to an ionic compound that exists as a liquid at 30 ° C.
  • a zwitterionic compound referring to an ionic compound that exists as a liquid at 30 ° C.
  • the manufacturing method of the secondary battery of this invention is not specifically limited, It can manufacture according to a well-known method.
  • the shape of the secondary battery of the present invention is not particularly limited, and a shape such as a coin shape, a sheet shape (film shape), a folded shape, a wound type bottomed cylindrical shape, a button shape, or the like is appropriately selected depending on the application. Can do.
  • the secondary battery of the present invention is provided with the positive electrode of the present invention, even if charging / discharging is repeated by increasing the upper limit of the cut-off voltage during charging (for example, 4.4 to 5.5 V), A decrease in capacity is suppressed.
  • the secondary battery of the present invention it is preferable to use an upper limit of the cutoff voltage during charging between 4.4 to 5.5V.
  • the secondary battery of the present invention is excellent in cycle characteristics even when the upper limit of the cut-off voltage during charging is increased, and is a secondary battery with higher capacity and higher output.
  • PVDF polyvinylidene fluoride
  • KF polymer # 1120 solid content 12%
  • N-methylpyrrolidone manufactured by Wako Pure Chemical Industries, Ltd.
  • Example 1 The coating liquid for forming a positive electrode active material layer obtained in Production Example 1 was applied onto an aluminum foil using an applicator, and the obtained coating film was dried at 80 ° C. for 1 hour. This was pressed at 70 ° C. and 2 MPa for 1 hour to obtain a laminated sheet comprising a current collector and a positive electrode active material layer. On the surface of the obtained laminated sheet, the ionic polymer layer forming coating solution obtained in Production Example 2 is applied, heated on a hot plate at 70 ° C. for 1 hour, and the basis weight of the ionic polymer An electrode sheet (positive electrode) of 0.39 mg / cm 2 was obtained.
  • Example 2 In Example 1, the coating amount of the ionic polymer layer forming coating solution was changed to obtain an electrode sheet having a basis weight of 0.23 mg / cm 2 of the ionic polymer.
  • FIG. 1 the horizontal axis represents the number of times of charging / discharging and the vertical axis represents the discharge capacity.
  • FIG. 1 Compared to Comparative Example 1, in Examples 1 and 2, a decrease in discharge capacity when charging and discharging are repeated is suppressed.
  • the secondary battery including the positive electrode of the present invention is less likely to have a reduced discharge capacity when the upper limit of the cutoff voltage during charging is increased and charging and discharging are repeated.

Abstract

The present invention is a positive electrode comprising: a charge collector; a positive-electrode active material layer formed on the charge collector; and an ionic polymer layer formed on the positive-electrode active material layer. The positive-electrode active material layer includes a positive-electrode active material. The ionic polymer layer includes an ionic polymer having repeating units originating from a monomer represented by formula (I). The basis weight of the ionic polymer layer is from 0.01 to 10 mg/cm2. Also disclosed are: a secondary battery comprising said positive electrode, a negative electrode, and an electrolyte component; and a method for using said secondary battery.

Description

正極、二次電池、及び二次電池の使用方法Positive electrode, secondary battery, and method of using secondary battery
　本発明は、サイクル特性に優れ、かつ、高容量の二次電池が得られる正極、この正極を備える二次電池、及び、この二次電池の使用方法に関する。 The present invention relates to a positive electrode with excellent cycle characteristics and a high-capacity secondary battery, a secondary battery including the positive electrode, and a method of using the secondary battery.
　近年、リチウムイオン電池等の二次電池においては、エネルギー密度を高め、軽量化及び小型化を達成することが要望されてきている。このため、作動電位の高い正極活物質を用いた、よりエネルギー密度の高い二次電池の研究開発が行われてきた。
　例えば、特許文献１には、特定の２種の酸化物を含む二次電池用正極活物質であって、５Ｖ級の二次電池のサイクル特性及び高温動作の信頼性の向上に寄与するものが記載されている。
　しかしながら、このような作動電位の高い正極活物質を用いた二次電池には、充電時のカットオフ電圧の上限を高くして充放電を繰り返すと、放電容量が急激に低下する場合があるという問題があった。このため、充放電を繰り返しても放電容量を低下させないためには、充電時のカットオフ電圧の上限を低くする必要があり、高容量の電池として使用することが困難であった。 In recent years, in secondary batteries such as lithium ion batteries, it has been desired to increase energy density and achieve weight reduction and size reduction. For this reason, research and development of a secondary battery having a higher energy density using a positive electrode active material having a high operating potential has been performed.
For example, Patent Document 1 discloses a positive electrode active material for a secondary battery containing two specific types of oxides, which contributes to improving the cycle characteristics of a 5V class secondary battery and the reliability of high-temperature operation. Are listed.
However, a secondary battery using such a positive electrode active material with a high operating potential may have a sudden decrease in discharge capacity when the upper limit of the cutoff voltage during charging is increased and charging and discharging are repeated. There was a problem. For this reason, in order not to reduce the discharge capacity even after repeated charging and discharging, it is necessary to lower the upper limit of the cut-off voltage during charging, and it has been difficult to use as a high-capacity battery.
特開２０１１－１３８７８７号公報JP2011-138787A
　本発明は、上記実情に鑑みてなされたものであり、サイクル特性に優れ（充放電を繰り返しても放電容量が低下し難い性質をいう）、かつ、高容量の二次電池が得られる正極、この正極を備える二次電池、及び、この二次電池の使用方法を提供することを目的とする。 The present invention has been made in view of the above circumstances, and is excellent in cycle characteristics (refers to a property in which the discharge capacity is not easily lowered even after repeated charge and discharge), and a positive electrode from which a high-capacity secondary battery is obtained, It aims at providing the secondary battery provided with this positive electrode, and the usage method of this secondary battery.
　本発明者らは上記課題を解決すべく鋭意検討した。その結果、集電体と、前記集電体上に形成された正極活物質層と、前記正極活物質層上に形成された、特定のイオン性重合体を特定量含有し、坪量が特定量であるイオン性重合体層とを有する正極を備える二次電池は、サイクル特性に優れ、かつ、高容量のものであることを見出し、本発明を完成するに至った。 The present inventors diligently studied to solve the above problems. As a result, the current collector, the positive electrode active material layer formed on the current collector, and a specific amount of a specific ionic polymer formed on the positive electrode active material layer are contained, and the basis weight is specified. A secondary battery including a positive electrode having an ionic polymer layer in an amount is found to have excellent cycle characteristics and a high capacity, and the present invention has been completed.
　かくして本発明によれば、下記（１）～（４）の正極、（５）の二次電池、及び（６）の二次電池の使用方法が提供される。
（１）集電体と、前記集電体上に形成された正極活物質層と、前記正極活物質層上に形成されたイオン性重合体層とを有する正極であって、前記正極活物質層が、正極活物質を含有するものであり、前記イオン性重合体層が、下記式（Ｉ） Thus, according to the present invention, the following positive electrodes (1) to (4), a secondary battery (5), and a method for using the secondary battery (6) are provided.
(1) A positive electrode comprising a current collector, a positive electrode active material layer formed on the current collector, and an ionic polymer layer formed on the positive electrode active material layer, wherein the positive electrode active material The layer contains a positive electrode active material, and the ionic polymer layer has the following formula (I)
Figure JPOXMLDOC01-appb-C000003
Figure JPOXMLDOC01-appb-C000003
（Ｘは、重合性炭素－炭素二重結合を有する、１の結合手を有する基を表し、Ｙは、炭素数２～５のアルキレン基を表し、Ｒ１、Ｒ２はそれぞれ独立に、水素原子、エーテル結合を有する若しくは有しない炭素数１～１０のアルキル基、エーテル結合を有する若しくは有しない炭素数２～１１のシアノアルキル基、エーテル結合を有する若しくは有しない炭素数２～１０のアルケニル基、又は、置換基を有する若しくは有しない炭素数６～２０のアリール基を表す。Ｒ１及びＲ２は、互いに結合して、環を形成していてもよい。）
で示される単量体に由来する繰り返し単位を有するイオン性重合体を含有するものであり、前記イオン性重合体層の坪量が、０．０１～１０ｍｇ／ｃｍ２である正極。
（２）前記Ｘが、下記式（ＩＩ）又は（ＩＩＩ） (X represents a group having a polymerizable carbon-carbon double bond and one bond, Y represents an alkylene group having 2 to 5 carbon atoms, and R 1 and R 2 are each independently hydrogen. C1-C10 alkyl group with or without atoms, ether bonds, C2-C11 cyanoalkyl groups with or without ether bonds, C2-C10 alkenyl groups with or without ether bonds Or an aryl group having 6 to 20 carbon atoms, with or without a substituent, R 1 and R 2 may be bonded to each other to form a ring.
A positive electrode comprising an ionic polymer having a repeating unit derived from the monomer represented by formula (1), wherein the ionic polymer layer has a basis weight of 0.01 to 10 mg / cm 2 .
(2) Said X is following formula (II) or (III)
Figure JPOXMLDOC01-appb-C000004
Figure JPOXMLDOC01-appb-C000004
（Ｒ３は、水素原子又はメチル基を表し、Ａ１は、炭素数１～１８のアルキレン基を表し、Ａ２、Ａ４はそれぞれ独立に、炭素数１～５のアルキレン基を表し、Ａ３は、単結合又は炭素数１～５のアルキレン基を表す。ｍは０～１０の整数を表し、ｎは０～１０の整数を表す。＊は結合手を表す。）
で示される基である、（１）に記載の正極。
（３）前記正極活物質層が、バインダー樹脂を含有するものである、（１）又は（２）に記載の正極。
（４）前記正極活物質層が、導電助剤を含有するものである、（１）又は（２）に記載の正極。
（５）前記（１）～（４）のいずれかに記載の正極、負極、及び電解質成分を有する二次電池。
（６）前記（５）に記載の二次電池の使用方法であって、充電時のカットオフ電圧の上限が４．４～５．５Ｖである、二次電池の使用方法。 (R 3 represents a hydrogen atom or a methyl group; A 1 represents an alkylene group having 1 to 18 carbon atoms; A 2 and A 4 each independently represents an alkylene group having 1 to 5 carbon atoms; 3 represents a single bond or an alkylene group having 1 to 5 carbon atoms, m represents an integer of 0 to 10, n represents an integer of 0 to 10, and * represents a bond.
The positive electrode according to (1), which is a group represented by:
(3) The positive electrode according to (1) or (2), wherein the positive electrode active material layer contains a binder resin.
(4) The positive electrode according to (1) or (2), wherein the positive electrode active material layer contains a conductive additive.
(5) A secondary battery comprising the positive electrode, negative electrode, and electrolyte component according to any one of (1) to (4).
(6) The method for using the secondary battery according to (5) above, wherein the upper limit of the cutoff voltage during charging is 4.4 to 5.5V.
　本発明によれば、サイクル特性に優れ、かつ、高容量の二次電池が得られる正極、この正極を備える二次電池、及び、この二次電池の使用方法が提供される。 According to the present invention, there are provided a positive electrode with excellent cycle characteristics and a high-capacity secondary battery, a secondary battery including the positive electrode, and a method of using the secondary battery.
実施例で行った定電流充放電試験の結果を表すグラフである。It is a graph showing the result of the constant current charging / discharging test done in the Example.
　以下、本発明を、１）正極、並びに、２）二次電池及びその使用方法、に項分けして詳細に説明する。 Hereinafter, the present invention will be described in detail by dividing it into 1) a positive electrode, and 2) a secondary battery and a method for using the secondary battery.
１）正極
　本発明の正極は、集電体と、前記集電体上に形成された正極活物質層と、前記正極活物質層上に形成されたイオン性重合体層とを有するものであって、前記正極活物質層が、正極活物質を含有するものであり、前記イオン性重合体層が、前記式（Ｉ）で示される単量体に由来する繰り返し単位を有するイオン性重合体を含有するものであり、前記イオン性重合体層の坪量が、０．０１～１０ｍｇ／ｃｍ２であるものである。 1) Positive Electrode The positive electrode of the present invention has a current collector, a positive electrode active material layer formed on the current collector, and an ionic polymer layer formed on the positive electrode active material layer. The positive electrode active material layer contains a positive electrode active material, and the ionic polymer layer comprises an ionic polymer having a repeating unit derived from the monomer represented by the formula (I). The basis weight of the ionic polymer layer is 0.01 to 10 mg / cm 2 .
　本発明の正極を構成する集電体は、正極活物質層を保持することができ、さらに、正極活物質層に含まれる正極活物質との間で電子の受け渡しを行うことができるものであれば、特に限定されない。
　正極集電体の材料は特に限定されない。例えば、アルミニウム、ニッケル、鉄、ステンレス鋼、チタン、銅等の金属材料や導電性高分子が挙げられる。 The current collector constituting the positive electrode of the present invention is capable of holding the positive electrode active material layer and further capable of transferring electrons to and from the positive electrode active material contained in the positive electrode active material layer. There is no particular limitation.
The material of the positive electrode current collector is not particularly limited. For example, metal materials and conductive polymers such as aluminum, nickel, iron, stainless steel, titanium, and copper can be used.
　本発明の正極を構成する正極活物質層は、前記集電体上に形成される。正極活物質層は、正極活物質を含有する。
　正極活物質は、二次電池の正極活物質として公知のものを適宜利用することができる。正極活物質としては、ＬｉＭｎ２Ｏ４、ＬｉＣｏＯ２、ＬｉＮｉＯ２、Ｌｉ（Ｎｉ－Ｍｎ－Ｃｏ）Ｏ２（例えば、ＬｉＮｉ１／３Ｍｎ１／３Ｃｏ１／３Ｏ２）、及び、これらの遷移金属の一部が他の元素により置換されたもの等の無機系活物質が挙げられる。 The positive electrode active material layer constituting the positive electrode of the present invention is formed on the current collector. The positive electrode active material layer contains a positive electrode active material.
As the positive electrode active material, a known material can be appropriately used as the positive electrode active material of the secondary battery. As the positive electrode active material, LiMn 2 O 4 , LiCoO 2 , LiNiO 2 , Li (Ni—Mn—Co) O 2 (for example, LiNi 1/3 Mn 1/3 Co 1/3 O 2 ), and these Examples thereof include inorganic active materials such as those in which a part of the transition metal is substituted with another element.
　正極活物質層は、バインダー樹脂や導電助剤を含有してもよい。
　正極活物質層がバインダー樹脂を含有するとき、バインダー樹脂は特に限定されず、公知のものを適宜利用することができる。
　バインダー樹脂としては、ポリフッ化ビニリデン（ＰＶＤＦ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、スチレン－ブタジエンゴム（ＳＢＲ）、ポリイミド（ＰＩ）、ポリアミドイミド（ＰＡＩ）、カルボキシメチルセルロース（ＣＭＣ）、ポリ塩化ビニル（ＰＶＣ）、メタクリル樹脂（ＰＭＡ）、ポリアクリロニトリル（ＰＡＮ）、変性ポリフェニレンオキシド（ＰＰＯ）、ポリエチレンオキシド（ＰＥＯ）、ポリエチレン（ＰＥ）、ポリプロピレン（ＰＰ）等が挙げられる。
　正極活物質層がバインダー樹脂を含有することにより、集電体上に正極活物質等がより強固に固定される。 The positive electrode active material layer may contain a binder resin and a conductive additive.
When the positive electrode active material layer contains a binder resin, the binder resin is not particularly limited, and known materials can be appropriately used.
Binder resins include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), polyimide (PI), polyamideimide (PAI), carboxymethylcellulose (CMC), and polyvinyl chloride (PVC). ), Methacrylic resin (PMA), polyacrylonitrile (PAN), modified polyphenylene oxide (PPO), polyethylene oxide (PEO), polyethylene (PE), polypropylene (PP) and the like.
When the positive electrode active material layer contains the binder resin, the positive electrode active material and the like are more firmly fixed on the current collector.
　正極活物質層が導電助剤を含有するとき、導電助剤は特に限定されず、公知のものを適宜利用することができる。
　導電助剤としては、カーボンブラック、グラファイト、黒鉛、カーボンナノチューブ、アセチレンブラック（ＡＢ）、ケッチェンブラック（ＫＢ）、気相成長炭素繊維等が挙げられる。
　正極活物質層が導電助剤を含有することにより、正極の導電性がより高められる。 When the positive electrode active material layer contains a conductive aid, the conductive aid is not particularly limited, and known materials can be used as appropriate.
Examples of the conductive assistant include carbon black, graphite, graphite, carbon nanotube, acetylene black (AB), ketjen black (KB), and vapor grown carbon fiber.
When the positive electrode active material layer contains a conductive additive, the conductivity of the positive electrode is further increased.
　本発明の正極を構成するイオン性重合体層は、下記式（Ｉ） The ionic polymer layer constituting the positive electrode of the present invention has the following formula (I)
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000005
（Ｘは、重合性炭素－炭素二重結合を有する、１の結合手を有する基を表し、Ｙは、炭素数２～５のアルキレン基を表し、Ｒ１、Ｒ２はそれぞれ独立に、水素原子、エーテル結合を有する若しくは有しない炭素数１～１０のアルキル基、エーテル結合を有する若しくは有しない炭素数２～１１のシアノアルキル基、エーテル結合を有する若しくは有しない炭素数２～１０のアルケニル基、又は置換若しくは無置換の炭素数６～２０のアリール基を表す。Ｒ１及びＲ２は、互いに結合して、環を形成していてもよい。）
で示される単量体に由来する繰り返し単位を有するイオン性重合体を含有する。 (X represents a group having a polymerizable carbon-carbon double bond and one bond, Y represents an alkylene group having 2 to 5 carbon atoms, and R 1 and R 2 are each independently hydrogen. C1-C10 alkyl group with or without atoms, ether bonds, C2-C11 cyanoalkyl groups with or without ether bonds, C2-C10 alkenyl groups with or without ether bonds Or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, R 1 and R 2 may be bonded to each other to form a ring.)
The ionic polymer which has a repeating unit derived from the monomer shown by is contained.
　Ｘに含まれる重合性炭素－炭素二重結合の種類は特に限定されない。ただし、後述するように、イオン性重合体の合成とイオン性重合体層の形成とを同時に行う（すなわち、塊状重合反応によりイオン性重合体を合成する）場合は、イオン性重合体層を効率よく形成することができることから、重合性炭素－炭素二重結合はラジカル重合反応に関与し得るものが好ましい。重合性炭素－炭素二重結合としては、アクリロイル基、メタアクリロイル基、ビニル基、アリル基に含まれる二重結合が挙げられる。
　Ｘとしては、下記式（ＩＩ）又は（ＩＩＩ）で示される基が挙げられる。 The kind of polymerizable carbon-carbon double bond contained in X is not particularly limited. However, as will be described later, when the synthesis of the ionic polymer and the formation of the ionic polymer layer are simultaneously performed (that is, the ionic polymer is synthesized by a bulk polymerization reaction), the ionic polymer layer is efficiently used. The polymerizable carbon-carbon double bond is preferably one that can participate in the radical polymerization reaction because it can be formed well. Examples of the polymerizable carbon-carbon double bond include double bonds contained in an acryloyl group, a methacryloyl group, a vinyl group, and an allyl group.
Examples of X include groups represented by the following formula (II) or (III).
Figure JPOXMLDOC01-appb-C000006
Figure JPOXMLDOC01-appb-C000006
　Ｒ３は、水素原子又はメチル基を表す。
　Ａ１は、炭素数１～１８のアルキレン基を表し、Ａ２、Ａ４はそれぞれ独立に、炭素数１～５のアルキレン基を表し、Ａ３は、単結合又は炭素数１～５のアルキレン基を表す。
　Ａ１の炭素数１～１８のアルキレン基としては、メチレン基、エチレン基、トリメチレン基、テトラメチレン基、ペンタメチレン基等の直鎖状アルキレン基；プロパン－１，２－ジイル基、ブタン－１，３－ジイル基等の分岐鎖状アルキレン基が挙げられる。Ａ２、Ａ４の炭素数１～５のアルキレン基としては、メチレン基、エチレン基、トリメチレン基、テトラメチレン基、ペンタメチレン基等の直鎖状アルキレン基；プロパン－１，２－ジイル基、ブタン－１，３－ジイル基等の分岐鎖状アルキレン基が挙げられる。 R 3 represents a hydrogen atom or a methyl group.
A 1 represents an alkylene group having 1 to 18 carbon atoms, A 2 and A 4 each independently represents an alkylene group having 1 to 5 carbon atoms, and A 3 represents a single bond or an alkylene group having 1 to 5 carbon atoms. Represents a group.
Examples of the alkylene group having 1 to 18 carbon atoms of A 1 include a linear alkylene group such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a pentamethylene group; a propane-1,2-diyl group, butane-1 , 3-diyl group, and the like. Examples of the alkylene group having 1 to 5 carbon atoms of A 2 and A 4 include a linear alkylene group such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a pentamethylene group; a propane-1,2-diyl group, Examples thereof include branched alkylene groups such as butane-1,3-diyl group.
　ｍは０～１０の整数を表し、好ましくは０～５、より好ましくは０～３である。
　ｎは０～１０の整数を表し、好ましくは０～５、より好ましくは０～３である。
　＊は、結合手を表す。 m represents an integer of 0 to 10, preferably 0 to 5, more preferably 0 to 3.
n represents an integer of 0 to 10, preferably 0 to 5, more preferably 0 to 3.
* Represents a bond.
　Ｘで表される基の具体例としては、ビニル基、アリル基、２－（メタクリロイルオキシ）エチル基、２－（アクリロイルオキシ）エチル基、３－（メタクリロイルオキシ）プロピル基、３－（アクリロイルオキシ）プロピル基等が挙げられる。
　これらの中でも、Ｘで表される基としては、ビニル基、アリル基、２－（メタクリロイルオキシ）エチル基、２－（アクリロイルオキシ）エチル基が好ましい。 Specific examples of the group represented by X include vinyl group, allyl group, 2- (methacryloyloxy) ethyl group, 2- (acryloyloxy) ethyl group, 3- (methacryloyloxy) propyl group, 3- (acryloyloxy). ) Propyl group and the like.
Among these, the group represented by X is preferably a vinyl group, an allyl group, a 2- (methacryloyloxy) ethyl group, or a 2- (acryloyloxy) ethyl group.
　式（Ｉ）中、Ｙは、炭素数２～５のアルキレン基を表す。
　Ｙの炭素数２～５のアルキレン基としては、エチレン基、トリメチレン基、テトラメチレン基、ペンタメチレン基等の直鎖状アルキレン基；プロパン－１，２－ジイル基、ブタン－１，３－ジイル基等の分岐鎖状アルキレン基が挙げられる。 In the formula (I), Y represents an alkylene group having 2 to 5 carbon atoms.
Examples of the alkylene group having 2 to 5 carbon atoms of Y include linear alkylene groups such as ethylene group, trimethylene group, tetramethylene group and pentamethylene group; propane-1,2-diyl group, butane-1,3-diyl And a branched alkylene group such as a group.
　Ｒ１、Ｒ２はそれぞれ独立に、水素原子、エーテル結合を有する若しくは有しない炭素数１～１０のアルキル基、エーテル結合を有する若しくは有しない炭素数２～１１のシアノアルキル基、エーテル結合を有する若しくは有しない炭素数２～１０のアルケニル基、又は、置換基を有する若しくは有しない炭素数６～２０のアリール基を表す。
　また、Ｒ１及びＲ２は、互いに結合して、環を形成していてもよい。 R 1 and R 2 each independently have a hydrogen atom, an alkyl group having 1 to 10 carbon atoms with or without an ether bond, a cyanoalkyl group having 2 to 11 carbon atoms with or without an ether bond, and an ether bond. Alternatively, it represents an alkenyl group having 2 to 10 carbon atoms which does not have, or an aryl group having 6 to 20 carbon atoms which may or may not have a substituent.
R 1 and R 2 may be bonded to each other to form a ring.
　Ｒ１、Ｒ２のエーテル結合を有する若しくは有しない炭素数１～１０のアルキル基の、炭素数１～１０のアルキル基の炭素数は、１～８が好ましく、１～５がより好ましい。
　エーテル結合を有しないアルキル基としては、メチル基、エチル基、ｎ－プロピル基、ｎ－ブチル基、ｎ－ペンチル基、ｎ－ヘキシル基等が挙げられる。
　エーテル結合を有するアルキル基としては、下記式で示される基等が挙げられる。 The number of carbon atoms of the alkyl group having 1 to 10 carbon atoms of the alkyl group having 1 to 10 carbon atoms with or without an ether bond of R 1 and R 2 is preferably 1 to 8, and more preferably 1 to 5.
Examples of the alkyl group having no ether bond include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group.
Examples of the alkyl group having an ether bond include groups represented by the following formulas.
Figure JPOXMLDOC01-appb-C000007
Figure JPOXMLDOC01-appb-C000007
（式中、Ｒ４は、炭素数１～８のアルキル基を表し、Ｚ１は、炭素数２～９のアルキレン基を表し、Ｒ４とＺ１の炭素数の合計は、３～１０である。Ｒ５は、炭素数１～６のアルキル基を表し、Ｚ２は、炭素数２～７のアルキレン基を表し、Ｚ３は、炭素数２～７のアルキレン基を表し、Ｒ５、Ｚ２、Ｚ３の炭素数の合計は、５～１０である。＊は結合手を表す。） (Wherein R 4 represents an alkyl group having 1 to 8 carbon atoms, Z 1 represents an alkylene group having 2 to 9 carbon atoms, and the total number of carbon atoms of R 4 and Z 1 is 3 to 10) R 5 represents an alkyl group having 1 to 6 carbon atoms, Z 2 represents an alkylene group having 2 to 7 carbon atoms, Z 3 represents an alkylene group having 2 to 7 carbon atoms, R 5 , (The total number of carbon atoms of Z 2 and Z 3 is 5 to 10. * represents a bond.)
　Ｒ１、Ｒ２のエーテル結合を有する若しくは有しない炭素数２～１１のシアノアルキル基の、炭素数２～１１のシアノアルキル基の炭素数は、２～９が好ましく、２～６がより好ましい。
　エーテル結合を有しないシアノアルキル基としては、シアノメチル基、２－シアノエチル基、３－シアノプロピル基、４－シアノブチル基、６－シアノヘキシル基等が挙げられる。
　エーテル結合を有するシアノアルキル基としては、下記式で示される基等が挙げられる。 The number of carbon atoms of the cyanoalkyl group having 2 to 11 carbon atoms in the cyanoalkyl group having 2 to 11 carbon atoms with or without an ether bond of R 1 and R 2 is preferably 2 to 9, and more preferably 2 to 6 .
Examples of the cyanoalkyl group having no ether bond include a cyanomethyl group, a 2-cyanoethyl group, a 3-cyanopropyl group, a 4-cyanobutyl group, and a 6-cyanohexyl group.
Examples of the cyanoalkyl group having an ether bond include groups represented by the following formulas.
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000008
（式中、Ｒ６は、炭素数２～９のシアノアルキル基を表し、Ｚ４は、炭素数２～９のアルキレン基を表し、Ｒ６とＺ４の炭素数の合計は、４～１１である。Ｒ７は、炭素数２～７のシアノアルキル基を表し、Ｚ５は、炭素数２～７のアルキレン基を表し、Ｚ６は、炭素数２～７のアルキレン基を表し、Ｒ７、Ｚ５、Ｚ６の炭素数の合計は、６～１１である。＊は結合手を表す。） (Wherein R 6 represents a cyanoalkyl group having 2 to 9 carbon atoms, Z 4 represents an alkylene group having 2 to 9 carbon atoms, and the total number of carbon atoms of R 6 and Z 4 is 4 to 11) R 7 represents a cyanoalkyl group having 2 to 7 carbon atoms, Z 5 represents an alkylene group having 2 to 7 carbon atoms, Z 6 represents an alkylene group having 2 to 7 carbon atoms, R 7 , Z 5 and Z 6 have a total carbon number of 6 to 11. * represents a bond.)
　Ｒ１、Ｒ２のエーテル結合を有する若しくは有しない炭素数２～１０のアルケニル基の、炭素数２～１０のアルケニル基の炭素数は、２～９が好ましく、２～６がより好ましい。
　エーテル結合を有しないアルケニル基としては、ビニル基、アリル基、１－ブテニル基、２－ブテニル基、１－ペンテニル基等が挙げられる。
　エーテル結合を有するアルケニル基としては、下記式で示される基等が挙げられる。 The carbon number of the alkenyl group having 2 to 10 carbon atoms of the alkenyl group having 2 to 10 carbon atoms with or without an ether bond of R 1 and R 2 is preferably 2 to 9, and more preferably 2 to 6.
Examples of the alkenyl group having no ether bond include a vinyl group, an allyl group, a 1-butenyl group, a 2-butenyl group, and a 1-pentenyl group.
Examples of the alkenyl group having an ether bond include groups represented by the following formulas.
Figure JPOXMLDOC01-appb-C000009
Figure JPOXMLDOC01-appb-C000009
（式中、Ｒ８は、炭素数２～８のアルケニル基を表し、Ｚ７は、炭素数２～８のアルキレン基を表し、Ｒ８とＺ７の炭素数の合計は、４～１０である。Ｒ９は、炭素数２～６のアルケニル基を表し、Ｚ８は、炭素数２～６のアルキレン基を表し、Ｚ９は、炭素数２～６のアルキレン基を表し、Ｒ９、Ｚ８、Ｚ９の炭素数の合計は、６～１０である。＊は結合手を表す。） (Wherein R 8 represents an alkenyl group having 2 to 8 carbon atoms, Z 7 represents an alkylene group having 2 to 8 carbon atoms, and the total number of carbon atoms of R 8 and Z 7 is 4 to 10) R 9 represents an alkenyl group having 2 to 6 carbon atoms, Z 8 represents an alkylene group having 2 to 6 carbon atoms, Z 9 represents an alkylene group having 2 to 6 carbon atoms, R 9 , (The total number of carbon atoms of Z 8 and Z 9 is 6 to 10. * represents a bond.)
　Ｒ１、Ｒ２の、置換基を有する若しくは有しない炭素数６～２０のアリール基の、炭素数６～２０のアリール基の炭素数は６～１０が好ましい。
　無置換のアリール基としては、フェニル基、１－ナフチル基、２－ナフチル基等が挙げられる。
　置換基を有するアリール基の置換基としては、メチル基、エチル基等の炭素数１～６のアルキル基；メトキシ基、エトキシ基等の炭素数１～６のアルコキシ基；フッ素原子、塩素原子等のハロゲン原子；等が挙げられる。 The aryl group having 6 to 20 carbon atoms and having or not having a substituent of R 1 and R 2 preferably has 6 to 10 carbon atoms.
Examples of the unsubstituted aryl group include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.
Examples of the substituent of the aryl group having a substituent include an alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group; an alkoxy group having 1 to 6 carbon atoms such as a methoxy group and an ethoxy group; a fluorine atom and a chlorine atom And the like.
　Ｒ１とＲ２が結合して形成される環としては、ピロリジン環、ピペリジン環等が挙げられる。 Examples of the ring formed by combining R 1 and R 2 include a pyrrolidine ring and a piperidine ring.
　式（Ｉ）で示される単量体の合成方法は特に限定されない。例えば、下記式に示すように、単量体（３）は、対応するアミン化合物（１）とスルトン化合物（２）とを反応させることにより得ることができる。 The method for synthesizing the monomer represented by the formula (I) is not particularly limited. For example, as shown in the following formula, the monomer (3) can be obtained by reacting the corresponding amine compound (1) with the sultone compound (2).
Figure JPOXMLDOC01-appb-C000010
Figure JPOXMLDOC01-appb-C000010
（上記式中、Ｘ、Ｒ１、Ｒ２は前記と同じ意味を表し、ｐは０、１、２又は３である。）
　アミン化合物（１）は、公知の方法で製造し、入手することができる。また、本発明においては、アミン化合物（１）として市販品を用いることもできる。 (In the above formula, X, R 1 and R 2 have the same meaning as described above, and p is 0, 1, 2 or 3.)
The amine compound (1) can be produced and obtained by a known method. Moreover, in this invention, a commercial item can also be used as an amine compound (1).
　前記スルトン化合物（２）としては、１，２－エタンスルトン、１，３－プロパンスルトン、１，４－ブタンスルトン、２，４－ブタンスルトン、１，５－ペンタンスルトンが挙げられる。
　これらは、公知化合物であり、公知の方法で製造し、入手することができる。また、本発明においては、これらのスルトン化合物として市販品を用いることもできる。 Examples of the sultone compound (2) include 1,2-ethane sultone, 1,3-propane sultone, 1,4-butane sultone, 2,4-butane sultone, and 1,5-pentane sultone.
These are known compounds and can be produced and obtained by known methods. Moreover, in this invention, a commercial item can also be used as these sultone compounds.
　アミン化合物（１）とスルトン化合物（２）との反応において、スルトン化合物（２）の使用量は、アミン化合物（１）に対して、好ましくは０．８～１．２当量、より好ましくは０．９～１．１当量である。スルトン化合物（２）の使用量を上記範囲にすることで、未反応物を除去する工程を省略したり、除去にかかる時間を短縮したりすることができる。 In the reaction of the amine compound (1) and the sultone compound (2), the amount of the sultone compound (2) used is preferably 0.8 to 1.2 equivalents, more preferably 0, relative to the amine compound (1). .9 to 1.1 equivalents. By making the usage-amount of a sultone compound (2) into the said range, the process of removing an unreacted substance can be abbreviate | omitted or the time concerning removal can be shortened.
　アミン化合物（１）とスルトン化合物（２）との反応は、無溶媒で行ってもよいし、不活性溶媒の存在下に行ってもよい。
　用いる不活性溶媒としては、テトラヒドロフラン、ジグライム等のエーテル系溶媒；アセトニトリル、プロピオニトリル等のニトリル系溶媒；アセトン、メチルエチルケトン等のケトン系溶媒；トルエン、キシレン等の芳香族炭化水素系溶媒；クロロホルム等のハロゲン化炭化水素系溶媒；等が挙げられる。
　不活性溶媒を用いる場合、その使用量は特に制限されないが、アミン化合物（１）１質量部に対して、通常１～１００質量部である。 The reaction of the amine compound (1) and the sultone compound (2) may be performed without a solvent or in the presence of an inert solvent.
Inert solvents used include ether solvents such as tetrahydrofuran and diglyme; nitrile solvents such as acetonitrile and propionitrile; ketone solvents such as acetone and methyl ethyl ketone; aromatic hydrocarbon solvents such as toluene and xylene; chloroform and the like And halogenated hydrocarbon solvents.
When an inert solvent is used, the amount used is not particularly limited, but is usually 1 to 100 parts by mass with respect to 1 part by mass of the amine compound (1).
　反応温度は、特に限定されないが、通常、０～２００℃、好ましくは１０～１００℃、より好ましくは２０～６０℃の範囲である。また、常圧(大気圧)下で反応を実施してもよいし、加圧条件下で反応を実施してもよい。
　反応時間は、特に限定されないが、通常、１２～３３２時間、好ましくは２４～１６８時間である。
　反応は、酸素による酸化や、空気中の水分によるスルトン化合物（２）の加水分解による収率の低下を防ぐ観点から、窒素ガス、アルゴンガス等の不活性ガス雰囲気下で行うことが好ましい。
　反応の進行は、ガスクロマトグラフィー、高速液体クロマトグラフィー、薄層クロマトグラフィー、ＮＭＲ、ＩＲ等の通常の分析手段により確認することができる。 The reaction temperature is not particularly limited, but is usually in the range of 0 to 200 ° C, preferably 10 to 100 ° C, more preferably 20 to 60 ° C. Further, the reaction may be carried out under normal pressure (atmospheric pressure), or the reaction may be carried out under pressurized conditions.
The reaction time is not particularly limited, but is usually 12 to 332 hours, preferably 24 to 168 hours.
The reaction is preferably performed in an inert gas atmosphere such as nitrogen gas or argon gas from the viewpoint of preventing the yield from decreasing due to oxidation by oxygen or hydrolysis of the sultone compound (2) by moisture in the air.
The progress of the reaction can be confirmed by ordinary analytical means such as gas chromatography, high performance liquid chromatography, thin layer chromatography, NMR, IR and the like.
　反応終了後、有機合成化学における通常の後処理操作を行い、所望により、再結晶、カラムクロマトグラフィー等の公知の精製方法により精製して、目的とする単量体を単離することができる。
　また、本発明においては、単量体として市販品を用いることもできる。 After completion of the reaction, normal post-treatment operations in organic synthetic chemistry are performed, and the desired monomer can be isolated by purification by a known purification method such as recrystallization or column chromatography, if desired.
Moreover, in this invention, a commercial item can also be used as a monomer.
　イオン性重合体の合成方法は特に限定されない。例えば、Ｘに含まれる重合性炭素－炭素二重結合がラジカル重合反応に関与し得るものであるときは、ラジカル重合開始剤を用いて重合反応を行うことにより、イオン性重合体を合成することができる。 The method for synthesizing the ionic polymer is not particularly limited. For example, when a polymerizable carbon-carbon double bond contained in X is capable of participating in a radical polymerization reaction, an ionic polymer is synthesized by performing a polymerization reaction using a radical polymerization initiator. Can do.
　ラジカル重合開始剤としては、有機過酸化物やアゾ系化合物等が挙げられる。
　有機過酸化物としては、ラウロイルパーオキサイド、ベンゾイルパーオキサイド等のジアシルパーオキサイド類；１，１－ビス（ｔ－ブチルパーオキシ）シクロヘキサン、１，１－ビス（ｔ－ブチルパーオキシ）３，３，５－トリメチルシクロヘキサン等のパーオキシケタール類；ジイソプロピルパーオキシジカーボネート、ジ－２－エチルヘキシルパーオキシジカーボネート等のパーオキシジカーボネート類；ｔ－ブチルパーオキシ－２－エチルヘキサノエート、ｔ－ブチルパーオキシイソブチレート等のパーオキシエステル類等が挙げられる。
　アゾ系化合物としては、２,２'－アゾビスイソブチロニトリル、２,２'－アゾビス(２－メチルブチロニトリル)、１,１'－アゾビス（シクロヘキサン１－カルボニトリル）、２,２'－アゾビス（２，４－ジメチルバレロニトリル）、２,２'－アゾビス（２，４－ジメチル－４－メトキシバレロニトリル）、ジメチル２,２'－アゾビス（２－メチルプロピオネート）、４,４'－アゾビス（４－シアノバレリック酸）、２,２'－アゾビス（２－ヒドロキシメチルプロピオニトリル）、２,２'－アゾビス［２－（２－イミダゾリン－２－イル）プロパン］等が挙げられる。
　これらは１種単独で、あるいは２種以上を混合して使用することができる。 Examples of the radical polymerization initiator include organic peroxides and azo compounds.
Examples of organic peroxides include diacyl peroxides such as lauroyl peroxide and benzoyl peroxide; 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) 3,3 Peroxyketals such as 1,5-trimethylcyclohexane; peroxydicarbonates such as diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate; t-butylperoxy-2-ethylhexanoate, t- And peroxyesters such as butyl peroxyisobutyrate.
As the azo compound, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane 1-carbonitrile), 2,2 '-Azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate), 4 , 4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile), 2,2'-azobis [2- (2-imidazolin-2-yl) propane] Etc.
These can be used individually by 1 type or in mixture of 2 or more types.
　ラジカル重合開始剤の使用量は、式（Ｉ）で示される単量体１モルに対し、通常０．２５～４倍モル、好ましくは０．４～２倍モルである。
　ラジカル重合反応の詳細は、正極の製造方法の中で説明する。 The amount of the radical polymerization initiator used is usually 0.25 to 4 times mol, preferably 0.4 to 2 times mol for 1 mol of the monomer represented by the formula (I).
The details of the radical polymerization reaction will be described in the method for producing the positive electrode.
　本発明の正極は、イオン性重合体層の坪量が、０．０１～１０ｍｇ／ｃｍ２のものである。イオン性重合体層の坪量は、好ましくは０．０１～５ｍｇ／ｃｍ２、より好ましくは０．１～１ｍｇ／ｃｍ２である。
　この量が０．０１ｍｇ／ｃｍ２未満の正極を備える二次電池はサイクル特性に劣る傾向がある。また、この量が１０ｍｇ／ｃｍ２を超えてもそれに見合った効果は得られない。
　イオン性重合体層の坪量とは、イオン性重合体層１ｃｍ２の質量をいう。イオン性重合体層がイオン性重合体のみからなる場合、イオン性重合体層の坪量とは、正極表面１ｃｍ２あたりに含まれる前記イオン性重合体の量である。 The positive electrode of the present invention has an ionic polymer layer having a basis weight of 0.01 to 10 mg / cm 2 . The basis weight of the ionic polymer layer is preferably 0.01 to 5 mg / cm 2 , more preferably 0.1 to 1 mg / cm 2 .
A secondary battery having a positive electrode with an amount of less than 0.01 mg / cm 2 tends to be inferior in cycle characteristics. Moreover, even if this amount exceeds 10 mg / cm < 2 >, the effect corresponding to it is not acquired.
The basis weight of the ionic polymer layer refers to the mass of 1 cm 2 of the ionic polymer layer. When an ionic polymer layer consists only of an ionic polymer, the basic weight of an ionic polymer layer is the quantity of the said ionic polymer contained per 1 cm < 2 > of positive electrode surfaces.
　本発明の正極は、集電体上に正極活物質層を形成し、次いで、この正極活物質層上にイオン性重合体層を形成することにより製造することができる。 The positive electrode of the present invention can be produced by forming a positive electrode active material layer on a current collector and then forming an ionic polymer layer on the positive electrode active material layer.
　正極活物質層の形成方法は特に限定されない。例えば、正極活物質、バインダー樹脂、及び導電助剤等を適当な溶媒に溶解又は懸濁させて得られた正極活物質層形成用塗工液を集電体上に塗工し、得られた塗膜を乾燥することにより正極活物質層を形成することができる。また、必要に応じて、乾燥後の塗膜に対して加圧処理を行ってもよい。 The method for forming the positive electrode active material layer is not particularly limited. For example, a positive electrode active material layer-forming coating solution obtained by dissolving or suspending a positive electrode active material, a binder resin, and a conductive auxiliary agent in an appropriate solvent was applied on a current collector, and obtained. The positive electrode active material layer can be formed by drying the coating film. Moreover, you may perform a pressurization process with respect to the coating film after drying as needed.
　正極活物質層形成用塗工液の調製に用いる溶媒は特に限定されない。用いる溶媒としては、Ｎ－メチルピロリドン、Ｎ，Ｎ－ジメチルホルムアミド、Ｎ，Ｎ－ジメチルアセトアミド等のアミド系溶媒；メチルエチルケトン、シクロヘキサノン等のケトン系溶媒；酢酸メチル、酢酸エチル等のエステル系溶媒；トルエン、キシレン等の芳香族系溶媒；等が挙げられる。 The solvent used for preparing the coating liquid for forming the positive electrode active material layer is not particularly limited. Solvents used include amide solvents such as N-methylpyrrolidone, N, N-dimethylformamide and N, N-dimethylacetamide; ketone solvents such as methyl ethyl ketone and cyclohexanone; ester solvents such as methyl acetate and ethyl acetate; toluene And aromatic solvents such as xylene;
　正極活物質層形成用塗工液を塗工する方法は特に限定されない。例えば、ダイコーター、グラビアコーター、ドクターブレード等の塗工装置を使用して正極活物質層形成用塗工液を塗工することができる。
　塗膜の乾燥条件は特に限定されない。例えば、３０～１５０℃で、１分から１２時間の範囲で適宜設定することができる。
　加圧処理を行う場合、その方法は特に限定されない。例えば、ロールプレス法や面押しプレス法により、加圧処理を行うことができる。加圧条件は、例えば、ロールプレス法の場合は、２０～１００℃、１００～２０００ｋｇ／ｃｍで、１分から１２時間の範囲で適宜設定することができる。また加工条件が面押しプレス法の場合は、２０～１００℃、１～２０ＭＰａで、１分から１２時間の範囲で適宜設定することができる。 The method for applying the positive electrode active material layer forming coating solution is not particularly limited. For example, the coating liquid for forming the positive electrode active material layer can be applied using a coating apparatus such as a die coater, a gravure coater, a doctor blade or the like.
The drying conditions of the coating film are not particularly limited. For example, the temperature can be appropriately set at 30 to 150 ° C. within a range of 1 minute to 12 hours.
When performing the pressure treatment, the method is not particularly limited. For example, the pressure treatment can be performed by a roll press method or a surface press method. For example, in the case of the roll press method, the pressurizing condition can be appropriately set within a range of 1 minute to 12 hours at 20 to 100 ° C. and 100 to 2000 kg / cm. In the case of the surface pressing method, the processing conditions can be appropriately set at 20 to 100 ° C. and 1 to 20 MPa in the range of 1 minute to 12 hours.
　イオン性重合体層の形成方法は特に限定されない。例えば、イオン性重合体を適当な溶媒に溶解又は懸濁させて得られたイオン性重合体層形成用塗工液（α）を正極活物質層上に塗工し、得られた塗膜を乾燥することによりイオン性重合体層を形成する方法（方法１）や、式（Ｉ）で示される単量体及びラジカル重合開始剤を適当な溶媒に溶解又は懸濁させて得られたイオン性重合体層形成用塗工液（β）を正極活物質層上に塗工し、必要に応じて得られた塗膜を乾燥した後、この塗膜中の単量体を重合させることにより、イオン性重合体層を形成する方法（方法２）等が挙げられる。
　目的の特性を有する正極をより効率よく製造することができることから、本発明においては、方法２を使用してイオン性重合体層を形成することが好ましい。 The formation method of an ionic polymer layer is not specifically limited. For example, an ionic polymer layer-forming coating solution (α) obtained by dissolving or suspending an ionic polymer in a suitable solvent is applied onto the positive electrode active material layer, and the resulting coating film is applied. A method of forming an ionic polymer layer by drying (Method 1), or an ionicity obtained by dissolving or suspending the monomer represented by the formula (I) and a radical polymerization initiator in an appropriate solvent By coating the coating liquid for forming a polymer layer (β) on the positive electrode active material layer and drying the coating film obtained as necessary, by polymerizing the monomers in the coating film, The method (method 2) etc. which form an ionic polymer layer are mentioned.
In the present invention, it is preferable to form the ionic polymer layer using the method 2 because a positive electrode having the desired characteristics can be produced more efficiently.
　方法２を使用してイオン性重合体層を形成する場合、イオン性重合体層形成用塗工液（β）を構成する溶媒は、単量体等を溶解又は分散し得るものであり、電極に対して濡れ性が低くなければ（塗布してもはじかなければ）特に限定されない。より均一な溶液又は分散液が得られ易いことから、用いる溶媒としては、トリクロロメタノール、２，２，２－トリクロロエタノール、３－クロロ－１－プロパノール等のハロゲン含有アルコールが好ましい。 When forming an ionic polymer layer using Method 2, the solvent constituting the ionic polymer layer-forming coating solution (β) can dissolve or disperse monomers and the like. If the wettability is not low (if it does not repel even if applied), there is no particular limitation. The solvent used is preferably a halogen-containing alcohol such as trichloromethanol, 2,2,2-trichloroethanol, or 3-chloro-1-propanol because a more uniform solution or dispersion can be easily obtained.
　方法２において、イオン性重合体層形成用塗工液（β）を正極活物質層上に塗工する方法は特に限定されない。例えば、正極活物質層形成用塗工液を塗工する方法として示した方法と同様にしてイオン性重合体層形成用塗工液（β）を塗工することができる。
　塗膜の乾燥条件は特に限定されない。３０～１５０℃で、１分から１２時間の範囲で適宜設定することができる。なお、乾燥工程とその後の重合反応工程を区別しないで、塗膜の乾燥と単量体の重合反応を同時に行ってもよい。
　塗膜中の単量体を重合させるには、例えば、イオン性重合体層形成用塗工液（β）が重合開始剤としてラジカル重合開始剤を含有する場合には、塗膜を所定温度に加熱すればよい。加熱条件は、単量体のラジカル重合反応が進行する温度であれば、特に限定されない。加熱温度は、通常、４０～１５０℃で、１分から１２時間の範囲で適宜設定することができる。 In Method 2, the method of coating the ionic polymer layer forming coating solution (β) on the positive electrode active material layer is not particularly limited. For example, the ionic polymer layer forming coating solution (β) can be applied in the same manner as the method shown as the method for applying the positive electrode active material layer forming coating solution.
The drying conditions of the coating film are not particularly limited. It can be appropriately set at 30 to 150 ° C. within a range of 1 minute to 12 hours. In addition, you may perform the drying of a coating film, and the polymerization reaction of a monomer simultaneously, without distinguishing a drying process and a subsequent polymerization reaction process.
In order to polymerize the monomer in the coating film, for example, when the ionic polymer layer forming coating solution (β) contains a radical polymerization initiator as a polymerization initiator, the coating film is brought to a predetermined temperature. What is necessary is just to heat. The heating condition is not particularly limited as long as it is a temperature at which the monomer radical polymerization reaction proceeds. The heating temperature is usually 40 to 150 ° C. and can be appropriately set within a range of 1 minute to 12 hours.
　本発明の正極は、集電体と、前記集電体上に形成された正極活物質層と、前記正極活物質層上に形成されたイオン性重合体層とを有するものである。この正極を用いることで、サイクル特性に優れ、かつ、高容量の二次電池を得ることができる。 The positive electrode of the present invention has a current collector, a positive electrode active material layer formed on the current collector, and an ionic polymer layer formed on the positive electrode active material layer. By using this positive electrode, a secondary battery having excellent cycle characteristics and high capacity can be obtained.
２）二次電池及びその使用方法
　本発明の二次電池は、本発明の正極、負極、及び電解質成分を有するものである。
　本発明の二次電池を構成する負極は、通常、負極集電体と負極活物質層とを含む。また、負極は、負極活物質層のみで構成されるもの（すなわち、負極活物質層が負極集電体を兼ねるもの）であってもよい。
　負極集電体は、負極活物質層を保持するとともに、負極活物質との電子の受け渡しを担うものである。
　負極集電体を構成する材料としては、正極集電体の材料として示したものと同様のものが挙げられる。
　負極活物質層は、負極集電体の表面に形成される層であり、そこには負極活物質が含まれる。負極活物質としては、グラファイト、ソフトカーボン、ハードカーボン等の炭素材料；Ｌｉ４Ｔｉ５Ｏ１２等のリチウム－遷移金属複合酸化物；ケイ素単体、ケイ素酸化物、ケイ素合金等のケイ素材料；リチウム金属；リチウム－スズまたはリチウム－ケイ素合金等のリチウム－金属合金；スズ材料等の単体、合金、化合物；ナトリウム、カリウム、マグネシウム等の周期律表第１族又は第２族の金属の単体、合金、化合物；硫黄またはこれらの材料を併用した複合材料等が挙げられる。
　負極活物質層は、負極活物質に加えてその他の成分を含有してもよい。その他の成分としては、バインダー樹脂や導電助剤が挙げられる。負極活物質層に含まれるバインダー樹脂や導電助剤としては、正極活物質層中のバインダー樹脂や導電助剤として示したものと同様のものが挙げられる。 2) Secondary battery and method of use thereof The secondary battery of the present invention has the positive electrode, the negative electrode, and the electrolyte component of the present invention.
The negative electrode constituting the secondary battery of the present invention usually includes a negative electrode current collector and a negative electrode active material layer. The negative electrode may be composed of only the negative electrode active material layer (that is, the negative electrode active material layer also serves as the negative electrode current collector).
The negative electrode current collector holds the negative electrode active material layer and bears an electron transfer with the negative electrode active material.
Examples of the material constituting the negative electrode current collector include the same materials as those shown for the positive electrode current collector.
The negative electrode active material layer is a layer formed on the surface of the negative electrode current collector, and contains a negative electrode active material. Examples of the negative electrode active material include carbon materials such as graphite, soft carbon, and hard carbon; lithium-transition metal composite oxides such as Li 4 Ti 5 O 12 ; silicon materials such as silicon simple substance, silicon oxide, and silicon alloy; lithium metal A lithium-metal alloy such as lithium-tin or a lithium-silicon alloy; a simple substance such as a tin material, an alloy or a compound; a simple substance or an alloy of a metal of Group 1 or Group 2 of the periodic table such as sodium, potassium or magnesium; Compound: Sulfur or composite materials using these materials in combination.
The negative electrode active material layer may contain other components in addition to the negative electrode active material. Examples of other components include a binder resin and a conductive aid. Examples of the binder resin and the conductive auxiliary contained in the negative electrode active material layer include the same ones as those shown as the binder resin and the conductive auxiliary in the positive electrode active material layer.
　本発明の二次電池を構成する電解質成分は特に限定されない。電解質成分としては、例えば、電解質塩を有機溶媒に溶解させて得られる非水電解液、無機固体電解質、ポリマー電解質等が挙げられる。 The electrolyte component constituting the secondary battery of the present invention is not particularly limited. Examples of the electrolyte component include a non-aqueous electrolyte obtained by dissolving an electrolyte salt in an organic solvent, an inorganic solid electrolyte, a polymer electrolyte, and the like.
　非水電解液を構成する電解質塩は、周期律表第１族又は第２族の金属イオンを含むイオン性化合物である。
　金属イオンとしては、リチウムイオン、ナトリウムイオン、カリウムイオン等のアルカリ金属イオン；マグネシウムイオン；カルシウムイオン、ストロンチウムイオン等のアルカリ土類金属イオン；が挙げられる。
　電解質塩の陰イオンとしては、例えば、Ｃｌ－、Ｂｒ－、Ｉ－、ＡｌＣｌ４ －、Ａｌ２Ｃｌ７ －、ＢＦ４ －、Ｂ（ＣＮ）４ －、ＰＦ６ －、ＣｌＯ４ －、ＮＯ３ －、ＡｓＦ６ －、ＳｂＦ６ －、ＮｂＦ６ －、ＴａＦ６ －、Ｆ（ＨＦ）ｎ －、ＣＨ３ＣＯＯ－、ＣＦ３ＣＯＯ－、Ｃ３Ｆ７ＣＯＯ－、ＣＨ３ＳＯ３ －、ＣＦ３ＳＯ３ －、Ｃ４Ｆ９ＳＯ３ －、（ＦＳＯ２）２Ｎ－、（ＣＦ３ＳＯ２）２Ｎ－、（ＣＨ２ＦＳＯ２）２Ｎ－、（Ｃ２Ｆ５ＳＯ２）２Ｎ－、（ＣＦ３ＳＯ２）（ＣＦ３ＣＯ）Ｎ－、（ＣＮ）２Ｎ－、（ＣＦ３ＳＯ２）３Ｃ－等が挙げられる。 The electrolyte salt constituting the non-aqueous electrolyte is an ionic compound containing a metal ion of Group 1 or Group 2 of the periodic table.
Examples of the metal ions include alkali metal ions such as lithium ions, sodium ions, and potassium ions; magnesium ions; alkaline earth metal ions such as calcium ions and strontium ions.
Examples of the anion of the electrolyte salt include Cl − , Br − , I − , AlCl 4 − , Al 2 Cl 7 − , BF 4 − , B (CN) 4 − , PF 6 − , ClO 4 − , NO 3. − , AsF 6 − , SbF 6 − , NbF 6 − , TaF 6 − , F (HF) n − , CH 3 COO − , CF 3 COO − , C 3 F 7 COO − , CH 3 SO 3 − , CF 3 SO 3 − , C 4 F 9 SO 3 − , (FSO 2 ) 2 N − , (CF 3 SO 2 ) 2 N − , (CH 2 FSO 2 ) 2 N − , (C 2 F 5 SO 2 ) 2 N -, (CF 3 SO 2) (CF 3 CO) N -, (CN) 2 N -, (CF 3 SO 2) 3 C - , and the like.
　電解質塩としては、リチウム塩が好ましい。リチウム塩としては、リチウムビス（フルオロメタンスルホニル）アミド（ＬｉＮ（ＳＯ２ＣＨ２Ｆ）２）、リチウムビス（トリフルオロメタンスルホニル）アミド（ＬｉＮ（ＳＯ２ＣＦ３）２）、リチウムビス（２，２，２－トリフルオロエタンスルホニル）アミド（ＬｉＮ（ＳＯ２Ｃ２Ｈ２Ｆ３）２）、リチウムビス（ペンタフルオロエタンスルホニル）アミド（ＬｉＮ（ＳＯ２Ｃ２Ｆ５）２）、リチウムビス（フルオロスルホニル）アミド（ＬｉＮ（ＳＯ２Ｆ）２）、リチウムトリス（トリフルオロメタンスルホニル）メチド（ＬｉＣ（ＳＯ２ＣＦ３）３）、トリフルオロメタンスルホン酸リチウム（ＬｉＣＦ３ＳＯ３）、ヘキサフルオロリン酸リチウム（ＬｉＰＦ６）、リチウムテトラフルオロボレート（ＬｉＢＦ４）、リチウムテトラシアノボレート（ＬｉＢ（ＣＮ）４）、リチウムビスオキサレートボレート（ＬｉＢ（Ｃ２Ｏ４）２）、過塩素酸リチウム（ＬｉＣｌＯ４）、ヘキサフルオロヒ酸リチウム（ＬｉＡｓＦ６）等が挙げられる。
　電解質塩は、１種単独で、あるいは２種以上を組み合わせて用いることができる。 As the electrolyte salt, a lithium salt is preferable. Examples of lithium salts include lithium bis (fluoromethanesulfonyl) amide (LiN (SO 2 CH 2 F) 2 ), lithium bis (trifluoromethanesulfonyl) amide (LiN (SO 2 CF 3 ) 2 ), lithium bis (2,2 , 2-trifluoroethanesulfonyl) amide (LiN (SO 2 C 2 H 2 F 3 ) 2 ), lithium bis (pentafluoroethanesulfonyl) amide (LiN (SO 2 C 2 F 5 ) 2 ), lithium bis (fluoro Sulfonyl) amide (LiN (SO 2 F) 2 ), lithium tris (trifluoromethanesulfonyl) methide (LiC (SO 2 CF 3 ) 3 ), lithium trifluoromethanesulfonate (LiCF 3 SO 3 ), lithium hexafluorophosphate ( LiPF 6 ), lithium tetrafluorobore (LiBF 4 ), lithium tetracyanoborate (LiB (CN) 4 ), lithium bisoxalate borate (LiB (C 2 O 4 ) 2 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate ( LiAsF 6), and the like.
The electrolyte salt can be used alone or in combination of two or more.
　有機溶媒としては、例えば、カーボネート系溶媒、エステル系溶媒、ラクトン系溶媒、エーテル系溶媒、ニトリル系溶媒、及び含硫黄系溶媒等が挙げられる。
　カーボネート系溶媒としては、ジメチルカーボネート、ジエチルカーボネート、ジプロピルカーボネート、メチルプロピルカーボネート、エチルプロピルカーボネート、メチルエチルカーボネート、エチルメチルカーボネート、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、ビニレンカーボネート等、または、これらのフッ素化物等が挙げられる。
　エステル系溶媒としては、前記エステル系溶媒としては、ｎ－メチルアセテート、ｎ－エチルアセテート、ｎ－プロピルアセテート、ジメチルアセテート等が挙げられる。
　ラクトン系溶媒としては、γ－ブチロラクトン、バレロラクトン、メバロノラクトン、カプロラクトン等が挙げられる。
　エーテル系溶媒としては、テトラヒドロフラン、２－メチルテトラヒドロフラン等の環状エーテル類；ジブチルエーテル、１，２－ジメトキシエタン、１，２－ジブトキシエタン、１，４－ジオキサン等の鎖状エーテル類；が挙げられる。
　ニトリル系溶媒としては、アセトニトリル、プロピオニトリル等が挙げられる。
　含硫黄系溶媒としては、スルホラン、ジメチルスルホキシド等が挙げられる。 Examples of the organic solvent include carbonate solvents, ester solvents, lactone solvents, ether solvents, nitrile solvents, and sulfur-containing solvents.
Examples of carbonate solvents include dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl ethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, or fluorines thereof. And the like.
Examples of the ester solvent include n-methyl acetate, n-ethyl acetate, n-propyl acetate, and dimethyl acetate.
Examples of the lactone solvent include γ-butyrolactone, valerolactone, mevalonolactone, caprolactone and the like.
Examples of ether solvents include cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran; chain ethers such as dibutyl ether, 1,2-dimethoxyethane, 1,2-dibutoxyethane, and 1,4-dioxane; It is done.
Examples of nitrile solvents include acetonitrile and propionitrile.
Examples of the sulfur-containing solvent include sulfolane and dimethyl sulfoxide.
　電解質成分として液状の電解液を用いる場合、通常、セパレーターが設けられる。セパレーターは正極と負極とを絶縁してショートを防止する一方で、イオンを通過させるという機能を有する。セパレーターを構成する材料としては、ポリエチレン、ポリプロピレン、ポリイミド等の絶縁性プラスチックで形成された多孔体や、シリカゲル等の無機微粒子が挙げられる。 When a liquid electrolyte is used as the electrolyte component, a separator is usually provided. The separator has a function of allowing ions to pass through while preventing a short circuit by insulating the positive electrode and the negative electrode. Examples of the material constituting the separator include a porous body formed of an insulating plastic such as polyethylene, polypropylene, and polyimide, and inorganic fine particles such as silica gel.
　無機固体電解質としては、窒化リチウム、ヨウ化リチウム等が挙げられる。
　ポリマー電解質を構成する高分子化合物としては、ポリエチレンオキサイド、ポリプロピレンオキサイド、ポリホスファゼン、ポリアジリジン、ポリエチレンスルフィド、ポリビニルアルコール、ポリフッ化ビニリデン、ポリヘキサフルオロプロピレン、フッ素系高分子化合物等が挙げられる。 Examples of the inorganic solid electrolyte include lithium nitride and lithium iodide.
Examples of the polymer compound constituting the polymer electrolyte include polyethylene oxide, polypropylene oxide, polyphosphazene, polyaziridine, polyethylene sulfide, polyvinyl alcohol, polyvinylidene fluoride, polyhexafluoropropylene, and a fluorine-based polymer compound.
　電解質成分は、イオン液体（３０℃で液体として存在するイオン性化合物をいう）、プラスティッククリスタルや、双性イオン化合物等の添加剤を含有してもよい。 The electrolyte component may contain an additive such as an ionic liquid (referring to an ionic compound that exists as a liquid at 30 ° C.), a plastic crystal, and a zwitterionic compound.
　本発明の二次電池の製造方法は特に限定されず、公知の方法に従って製造することができる。
　本発明の二次電池の形状は特に限定されず、コイン型、シート状（フィルム状）、折り畳み状、巻回型有底円筒型、ボタン型等の形状を、用途に応じて適宜選択することができる。 The manufacturing method of the secondary battery of this invention is not specifically limited, It can manufacture according to a well-known method.
The shape of the secondary battery of the present invention is not particularly limited, and a shape such as a coin shape, a sheet shape (film shape), a folded shape, a wound type bottomed cylindrical shape, a button shape, or the like is appropriately selected depending on the application. Can do.
　本発明の二次電池は、本発明の正極を備えるものであるため、充電時のカットオフ電圧の上限を高くして（例えば、４．４～５．５Ｖ）充放電を繰り返しても、放電容量の低下が抑制される。
　本発明の二次電池を使用する際は、充電時のカットオフ電圧の上限を４．４～５．５Ｖの間で使用することが好ましい。
　このように、本発明の二次電池は、充電時のカットオフ電圧の上限を高くしてもサイクル特性に優れるものであり、より高容量かつ高出力の二次電池である。 Since the secondary battery of the present invention is provided with the positive electrode of the present invention, even if charging / discharging is repeated by increasing the upper limit of the cut-off voltage during charging (for example, 4.4 to 5.5 V), A decrease in capacity is suppressed.
When the secondary battery of the present invention is used, it is preferable to use an upper limit of the cutoff voltage during charging between 4.4 to 5.5V.
As described above, the secondary battery of the present invention is excellent in cycle characteristics even when the upper limit of the cut-off voltage during charging is increased, and is a secondary battery with higher capacity and higher output.
　以下、実施例を挙げて本発明を更に詳細に説明する。但し、本発明は、以下の実施例になんら限定されるものではない。
　各例中の部及び％は、特に断りのない限り、質量基準である。 Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
Unless otherwise indicated, the part and% in each example are based on mass.
〔製造例１〕
　ＬｉＮｉ１／３Ｍｎ１／３Ｃｏ１／３Ｏ２（ＮＭＣ）（日下レアメタル研究所社製）３１．９ｇ、アセチレンブラック（電気化学工業社製、デンカブラック）２．２５ｇを乳鉢上ですりつぶしながら混合し、次いで、ＰＶＤＦ（ポリフッ化ビニリデン）溶液（クレハ・バッテリー・マテリアルズ・ジャパン社製、ＫＦポリマー♯１１２０、固形分１２％）２７．５ｇ、Ｎ－メチルピロリドン（和光純薬工業社製）５４ｇを混合し、ホモジナイザーで３０分間攪拌し、正極活物質層形成用塗工液を得た。 [Production Example 1]
Grind 31.9 g of LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC) (manufactured by Kusaka Rare Metal Laboratories) and 2.25 g of acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd., Denka Black) on a mortar. Then, 27.5 g of PVDF (polyvinylidene fluoride) solution (manufactured by Kureha Battery Materials Japan, KF polymer # 1120, solid content 12%), N-methylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd.) ) 54 g was mixed and stirred with a homogenizer for 30 minutes to obtain a positive electrode active material layer forming coating solution.
〔製造例２〕
　［２－（メタクリロイルオキシ）エチル］ジメチル（３－スルホプロピル）アンモニウム（シグマアルドリッチ社製）０．１ｇ、及び２，２’－アゾビスイソブチロニトリル（ＡＩＢＮ）（和光純薬工業社製）１ｍｇを、２，２，２－トリクロロエタノール１０ｇに溶解させ、イオン性重合体層形成用塗工液を得た。 [Production Example 2]
[2- (Methacryloyloxy) ethyl] dimethyl (3-sulfopropyl) ammonium (manufactured by Sigma-Aldrich) 0.1 g, and 2,2′-azobisisobutyronitrile (AIBN) (manufactured by Wako Pure Chemical Industries, Ltd.) 1 mg was dissolved in 10 g of 2,2,2-trichloroethanol to obtain a coating solution for forming an ionic polymer layer.
〔実施例１〕
　製造例１で得た正極活物質層形成用塗工液を、アプリケーターを用いてアルミ箔上に塗工し、得られた塗膜を８０℃で１時間乾燥した。このものを７０℃、２ＭＰａで１時間プレスし、集電体と正極活物質層からなる積層シートを得た。
　得られた積層シートの表面に、製造例２で得たイオン性重合体層形成用塗工液を塗工し、ホットプレート上で７０℃、１時間加熱し、イオン性重合体の坪量が０．３９ｍｇ/ｃｍ２の電極シート（正極）を得た。 [Example 1]
The coating liquid for forming a positive electrode active material layer obtained in Production Example 1 was applied onto an aluminum foil using an applicator, and the obtained coating film was dried at 80 ° C. for 1 hour. This was pressed at 70 ° C. and 2 MPa for 1 hour to obtain a laminated sheet comprising a current collector and a positive electrode active material layer.
On the surface of the obtained laminated sheet, the ionic polymer layer forming coating solution obtained in Production Example 2 is applied, heated on a hot plate at 70 ° C. for 1 hour, and the basis weight of the ionic polymer An electrode sheet (positive electrode) of 0.39 mg / cm 2 was obtained.
〔実施例２〕
　実施例１において、イオン性重合体層形成用塗工液の塗工量を変更し、イオン性重合体の坪量が０．２３ｍｇ/ｃｍ２の電極シートを得た。 [Example 2]
In Example 1, the coating amount of the ionic polymer layer forming coating solution was changed to obtain an electrode sheet having a basis weight of 0.23 mg / cm 2 of the ionic polymer.
〔比較例１〕
　実施例１の電極シートを製造する際に用いた集電体と正極活物質層からなる積層シートを比較例１の正極として用いた。 [Comparative Example 1]
The laminated sheet consisting of the current collector and the positive electrode active material layer used when manufacturing the electrode sheet of Example 1 was used as the positive electrode of Comparative Example 1.
（定電流充放電試験）
　実施例１、２及び比較例１で得た正極を用いて、以下の条件で充放電試験を行った。
装置：Ｂｉｏｌｏｇｉｃ社製モジュール型ポテンショスタット／ガルバノスタット（ＶＭＰ－３００）
測定温度：４０℃
カットオフ電圧：３．０～４．６Ｖ
正極：実施例又は比較例の電極シート
負極：リチウム箔
セパレーター：グラスフィルター（アドバンテック社製、ＧＡ－５５）
電流密度：６５９μＡ/ｃｍ２ (Constant current charge / discharge test)
Using the positive electrodes obtained in Examples 1 and 2 and Comparative Example 1, a charge / discharge test was performed under the following conditions.
Apparatus: Module type potentiostat / galvanostat (VMP-300) manufactured by Biologic
Measurement temperature: 40 ° C
Cut-off voltage: 3.0 to 4.6V
Positive electrode: Electrode sheet of Example or Comparative Example Negative electrode: Lithium foil separator: Glass filter (manufactured by Advantech, GA-55)
Current density: 659 μA / cm 2
　得られた結果を図１に示す。図１中、横軸は充放電の回数を表し、縦軸は放電容量を表す。
　図１から以下のことが分かる。
　比較例１に比べて、実施例１、２においては、充放電を繰り返したときの放電容量の低下が抑制されている。このように、本発明の正極を備える二次電池は、充電時のカットオフ電圧の上限を高くして充放電を繰り返した場合に、放電容量がより低下し難くいものである。 The obtained results are shown in FIG. In FIG. 1, the horizontal axis represents the number of times of charging / discharging and the vertical axis represents the discharge capacity.
The following can be seen from FIG.
Compared to Comparative Example 1, in Examples 1 and 2, a decrease in discharge capacity when charging and discharging are repeated is suppressed. As described above, the secondary battery including the positive electrode of the present invention is less likely to have a reduced discharge capacity when the upper limit of the cutoff voltage during charging is increased and charging and discharging are repeated.

Claims (6)

  1. 　集電体と、前記集電体上に形成された正極活物質層と、前記正極活物質層上に形成されたイオン性重合体層とを有する正極であって、
    　前記正極活物質層が、正極活物質を含有するものであり、
    　前記イオン性重合体層が、下記式（Ｉ）
    Figure JPOXMLDOC01-appb-C000001
     （Ｘは、重合性炭素－炭素二重結合を有する、１の結合手を有する基を表し、Ｙは、炭素数２～５のアルキレン基を表し、Ｒ１、Ｒ２はそれぞれ独立に、水素原子、エーテル結合を有する若しくは有しない炭素数１～１０のアルキル基、エーテル結合を有する若しくは有しない炭素数２～１１のシアノアルキル基、エーテル結合を有する若しくは有しない炭素数２～１０のアルケニル基、又は、置換基を有する若しくは有しない炭素数６～２０のアリール基を表す。Ｒ１及びＲ２は、互いに結合して、環を形成していてもよい。）
    で示される単量体に由来する繰り返し単位を有するイオン性重合体を含有するものであり、
    　前記イオン性重合体層の坪量が、０．０１～１０ｍｇ／ｃｍ２である正極。     A positive electrode having a current collector, a positive electrode active material layer formed on the current collector, and an ionic polymer layer formed on the positive electrode active material layer,
    The positive electrode active material layer contains a positive electrode active material,
    The ionic polymer layer has the following formula (I)
    Figure JPOXMLDOC01-appb-C000001
     (X represents a group having a polymerizable carbon-carbon double bond and one bond, Y represents an alkylene group having 2 to 5 carbon atoms, and R 1 and R 2 are each independently hydrogen. C1-C10 alkyl group with or without atoms, ether bonds, C2-C11 cyanoalkyl groups with or without ether bonds, C2-C10 alkenyl groups with or without ether bonds Or an aryl group having 6 to 20 carbon atoms, with or without a substituent, R 1 and R 2 may be bonded to each other to form a ring.
    Containing an ionic polymer having a repeating unit derived from the monomer represented by
    A positive electrode in which the basis weight of the ionic polymer layer is 0.01 to 10 mg / cm 2 .
  2. 　前記Ｘが、下記式（ＩＩ）又は（ＩＩＩ）
    Figure JPOXMLDOC01-appb-C000002
     （Ｒ３は、水素原子又はメチル基を表し、Ａ１は、炭素数１～１８のアルキレン基を表し、Ａ２、Ａ４は、それぞれ独立に、炭素数１～５のアルキレン基を表し、Ａ３は、単結合又は炭素数１～５のアルキレン基を表す。ｍは０～１０の整数を表し、ｎは０～１０の整数を表す。＊は結合手を表す。）
    で示される基である、請求項１に記載の正極。     X represents the following formula (II) or (III)
    Figure JPOXMLDOC01-appb-C000002
     (R 3 represents a hydrogen atom or a methyl group, A 1 represents an alkylene group having 1 to 18 carbon atoms, A 2 and A 4 each independently represents an alkylene group having 1 to 5 carbon atoms, A 3 represents a single bond or an alkylene group having 1 to 5 carbon atoms, m represents an integer of 0 to 10, n represents an integer of 0 to 10, and * represents a bond.)
    The positive electrode according to claim 1, which is a group represented by:
  3. 　前記正極活物質層が、バインダー樹脂を含有するものである、請求項１又は２に記載の正極。 The positive electrode according to claim 1 or 2, wherein the positive electrode active material layer contains a binder resin.
  4. 　前記正極活物質層が、導電助剤を含有するものである、請求項１又は２に記載の正極。 The positive electrode according to claim 1 or 2, wherein the positive electrode active material layer contains a conductive additive.
  5. 　請求項１～４のいずれかに記載の正極、負極、及び電解質成分を有する二次電池。 A secondary battery comprising the positive electrode according to any one of claims 1 to 4, a negative electrode, and an electrolyte component.
  6. 　請求項５に記載の二次電池の使用方法であって、充電時のカットオフ電圧の上限が４．４～５．５Ｖである、二次電池の使用方法。 The method for using a secondary battery according to claim 5, wherein the upper limit of the cutoff voltage during charging is 4.4 to 5.5V.
PCT/JP2016/079485 2015-10-05 2016-10-04 Positive electrode, secondary battery, and method for using secondary battery WO2017061424A1 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007080642A (en) * 2005-09-13 2007-03-29 Sumitomo Bakelite Co Ltd Electrolyte resin composition, ion conductive electrolyte, and secondary battery using it
WO2015065004A1 (en) * 2013-10-29 2015-05-07 주식회사 엘지화학 Gel polymer electrolyte and lithium secondary battery including same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007080642A (en) * 2005-09-13 2007-03-29 Sumitomo Bakelite Co Ltd Electrolyte resin composition, ion conductive electrolyte, and secondary battery using it
WO2015065004A1 (en) * 2013-10-29 2015-05-07 주식회사 엘지화학 Gel polymer electrolyte and lithium secondary battery including same

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